If you're already stuffing your sweater into your purse or day bag, congratulations, you're way ahead of the trend! The downside, you may already know, is that when you drag the sweater back out of your bag, it's wrinkled and, if your bag is anything like mine, covered with bits of fluff, loose change, and potentially a lipstick smudge or two.

It turns out that there are actually sweaters built to withstand this cycle of need and neglect. I compared three—the Secret Sweater, Chilly Jilly, and Pocket Poppet—side by side and discovered that, while at first glance they may seem interchangeable, each has key features that make it useful for a particular kind of traveler/purse-sweater-stuffer.

Common Features

All three sweaters share some useful features. They all fold up small and pack easily into an included cloth bag. They're all wrinkle resistant and, even if you do a careless job of stuffing the sweater into its sack, any wrinkles just disappear after a few minutes of wear the next time you put the sweater on. They're all quite flattering and adaptable and can be dressed up or down. And they all need to be machine washed on cold and air-dried.

What Sets Each Apart

Secret Sweater

(Photo: Secret Sweater)

Consider the Secret Sweater part sweater, part insulation. It's meant as a light layer on its own or a low-profile layer under a not-quite-warm-enough blazer, jacket, or sweater. The smallest (and smallest-packing) of the bunch, this sweater hits mid-torso and has three-quarter-length sleeves. It's soft, and it feels most like cotton. The Secret Sweater comes in four colors.

Fabrics: 50 percent cotton, 50 percent modal

Best As: An easy-to-stash (even in an evening bag) layer that adds warmth but fits invisibly under a jacket

Pocket Poppet

(Photo: Pocket Poppet)

The Pocket Poppet is a simple sweater with nice details, including a bit of sleeve ruching at the wrist, drapey pleating in front, and a box pleat and band at the back. It's the only one of these sweaters with the pocket actually built in. It hangs unobtrusively on the inside of the sweater's back and can be used to store small items. It's soft, comfortable, and while it's relatively thin, it manages the chill of, say, an airplane cabin or an air-conditioned store well. The "Classic" Pocket Poppet comes in seven colors.

Fabrics: 92 percent rayon, 8 percent spandex

Best As: A sweater with flattering details and a secret pocket

Chilly Jilly Jacket

(Photo: Chilly Jilly)

The Jilly Jacket is the largest when stuffed into its bag (though it's still fairly small, about the size of a pair of flats in size 8), but it is also the warmest of the three, and it managed to effectively substitute for a light jacket on a breezy day. The material is very lightweight and soft, and it comes in off-white and black. It has fewer details than the Poppet Pocket, but it does have more substantial draping in front, which you can pull across for a more scarf-like look and feel.